Change name for local CriticalSectionScoped variable

Tools were complaining about (harmless) shadowing of variable names.

This is a follow-up to
https://webrtc-codereview.appspot.com/41659004/#msg8

BUG=3926
TBR=kwiberg@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/37099004

Cr-Commit-Position: refs/heads/master@{#8225}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8225 4adac7df-926f-26a2-2b94-8c16560cd09d
1 file changed